1. Field of the Disclosure
The present disclosure relates to a semiconductor laser diode array, and more specifically, to a semiconductor laser diode array with dual semiconductor laser diode chips having two laser generating regions, which are attached to each other.
2. Description of the Related Art
A semiconductor laser diode uses the characteristics of a compound semiconductor to convert an electrical signal into laser light. Semiconductor laser diodes are used in various fields including image-forming apparatuses. For example, a semiconductor laser diode used in a light-scanning unit for an image-forming apparatus for printing an image on paper such as a printer or copier emits laser light to form an electrostatic latent image on a photoreceptor drum.
In recent years, the image-forming apparatus requires high-speed high-resolution printing. For high resolution printing, the image-forming apparatus employs a technique which scans a smaller spot diameter by using a nitride semiconductor blue laser diode instead of a conventional infrared or red laser diode. Also, for high speed printing, a method for simultaneously scanning a plurality of laser beams is being developed. Typically, laser diodes in a laser diode array for simultaneously emitting a plurality of laser beams should be arranged at small intervals, e.g., less than about 20 μm. Thus, the development of a compact nitride semiconductor laser diode array is a key technical task for achieving high-speed high resolution printing. In particular, because the interval between laser diodes in a semiconductor laser diode array is very small, it becomes critical to efficiently form a p-metal layer in order to independently drive each laser diode.